I recently shot a concert with a 15mm Fisheye Lens wide open on the highest available ISO. My initial assumption is that with a Fisheye lens I would be able to have the entire frame in focus no matter what aperture I was set on. My shooting style for this show was to set the camera to continuous mode and do a more shoot from the hip style firing off multiple bursts at key moments. That way I’d be able to enjoy the show while not looking through a view finder and still be able to capture the action of the performance.
While performing my post production workflow, I noticed that the subjects in a lot of my images were out of focus meanwhile the background was in focus. My thought is that my initial hypothesis needs to be tested and revised. So I decided to setup a study for this 15mm Fisheye. In preparation for an upcoming portfolio project, I did the same study on my two tilt shift lenses a 24mm and 45mm.
I setup one of my bass guitars on a table. I chose this subject knowing something like this would present me with a foreground, midground, and background. I setup some lights just for this test, locked my camera down on a tripod and set about making exposures at each F-Stop for the 3 lenses I’m attempting to better understand. I focused my craftsmanship more so on the DOF component and used this as an opportunity to work on lighting and metering and to see how shutter speed and ISO effect strobe exposure.
The following contact sheets are the result of this study. Both Tilt Shift Lenses where adjusted to their maximum degree angles in relation to the sensor plane. I focused on the “W” logo on the headstock each time for a point of reference.
My conclusions are that Fisheye Lenses, while not as extreme as more traditional focal lengths do indeed contribute some bokeh to an image on wide open settings. This can be mitigated by stopping down to smaller apertures.
You can really see the bokeh effect on the Tilt Shift lenses; especially the 45mm. Even on the smallest aperture, the back ground is out of focus.
For future concert shoots, I will have to use even higher ISO settings to be able to maintain a fast shutter speed and use smaller apertures. I have done the necessary menu diving in order to learn how to make this happen and have successfully unlocked up to 25600 on my camera body. I have noise mitigation strategies for my post production workflow.
I’ll get to retest my hypothesis soon.